Ski positioning means for airplanes



Aug l, 1.950 H. G. HAGER 2,517,481

SKI POSITIONING MEANS FOR AIRPLANES Filed May 24, 1949 IL .l l

54 I t si? so 40 0 la \57 22 3 \e RE HERBERT G. HAGER nnentor PatentedAug. 1, 1950 UNITED STATES PATENT `OFFICE'.

4 Claims.

My present invention relates to the generalart of ski landing gear forairplanes, and more spe.- cially to a ski positioning means 4forairplanes.

With the Igreatly increased use of airplanes in cold `countries :therehas been an unusual development in the iield oi' ski or skieboardlanding gears for such use. The majority of these observed have beenconstructed at considerable expense, and are designed to take care .ofthe larger aircrafts, `and many of` them provide, in addition to .askiattaching means, an additional stabilizing and shock absorbing gear.Such equipment is well placed on the larger expensive aircraft.I-Iowever, the eld of small planes has not been given very much study.

My invention consists essentially of a unit which may be substituted forthe usual wheels and .brake assembly on a. light airplane, and `providestwo parallel bars which .are encircled by a-plurality of strands oishock cord, one of which members is iixedwith the airplane, and theother xed `to the ski mount and held in positionnermally by the shockcords which encircle the two members. This provides .a resilient means4for keeping the ski in a Anormal flying position, and yet allows theski a 'limited degree of movement during landing or take-offs or iftaxiing is done over rough snow or ice.

The principal object of my present invention, therefore, islto provide alight, simple and economical ski landing gear `,which may be substitutedfor the usual wheelsonlight airplanes.

A further object of my invention is to provide means that will insurethat the landing ski will normally be held in its true flying positionso that a minimum of air Aresistanceiwill be encountered, and thiswithout the use of additional struts or cables extending from the skiattachment to the airplane body or Wings.

A further object of my invention is to provide a ski positioning meanswhich, while presenting the ski normal to the axis of the plane inlanding, will permit the ski to follow the ground contour as when anairplane lands at a considerable angle descent, or when rough snow orsnow drifts and the like are encountered.

A further object of my present invention is to I Figure `1 is ,aperspective Aview showing `the essential elements `ofmy invention asdetached from an `,airplane .and mounted upon a ski, parts of which arebroken away;

Figure 2 is a yertical sectional view takenalong the plane of line 2--2of 'Figure 1;

Figure 3 is va vertical sectional view taken along the line `of 3--3 ofFigure 2, and

Figure 4 is a reduced scale view, similar in par-t to Figure 3 but:show-ing the ski mount displaced from the airplane mount.

Referring more particularly to the disclosure in the drawings, thenumeral 6 designates the supporting axle of my device; this may beformed to 4slide over the usual airplane .axle employing wheels, and thesame is fixed against rotation by means which mustconform to the designofthe plane with whichwmy device is to be used. In many `cases thelperforated pad 8 can be xedly secured to the airplane landing gearsupport means. Fixedly secured to 4axle 6 is the vertically disposedshock pillar l-. This may be secured in any manner so as to be iixedwith respect to the airplane. I-have illustrated a flange l2,`whlc`h isiixedly secured to axle `tube E, and to which pillar `lil is secured asby `bolting thereto. In certain cases rotation `of `my device isprevented `by having bolts l 4 lock pillar Il) to the brake housing zandythe like, which, `in turn, are ilxedlysecured` as by weldingithereto,to bearing plates, as 25 and 26. These plates in turn are xedly securedto the landing skis 28. For additional reinforcement, the skis may havean added member 30 so as to further distribute the weight of the planeto the ski. Fixedly secured to the tubular axle I6, as by Weldingthereto, is the movable or ski pillar 33. This pillar, in order to gainadditional stiffness for the assembly, is further secured as by weldingto two of the downward extending legs, as is illustrated at 35.

Pillars lli and 33 have an upper assembly that is very similar in that acentral web is provided, which is preferably reinforced by beaded.edges, as 31 and 38. Each of the members is further provided with abottom ange, as 40 and 42, and similarly with an upper iiange, as 44 and45. These flange members form the bearing for, and the retaining meansfor, a plurality of resilient vided the limit slots 5l] and 52 in pillarIB, andy in the mating pillar 33 I provide bolt holes in which Iposition shock or shear bolts 54 and 55.

Attention is directed particularly to Figures 3y and 4. In Figure 4 itwill be noted that bolt 55 has come to the end of slot 52, and thereforelimits any further movement unless the force should be so great as toshear this bolt. When that occurs, the load is then transferred to boltl 54 which, owing tothe fact that its slotv 5G is longer and is closerto the center of revolution,`

can allow a ycontinued movement of the pillars against the shock cordsuntil the limit of slot 5i) is reached. If the landing force is verysevere, this bolt itself might be sheared and then reliance would haveto be placed upon the shock cords and the resiliency of the skisthemselves. It has been found in trial, however, that this step-bystepoverload feature adds a great deal to the safety of light airplanes onskis.

It is believed that it will be clearly apparent from the abovedescription and the disclosure in the drawings that the inventioncomprehends a novel construction of a ski positioning means forairplanes. v

Having thus disclosed the invention, I claim:

l. A ski positioning means for light airplanes, comprising: a tubularaxle adapted to be secured, xedly, to an airplane landing gear; avertically disposed shock pillar xedly secured to said axle; a ski axle,co-axially disposed with and revolvably supported by said tubular axle;means forsecuring said ski axle xedly to a landing ski;'a ski pillarfixedly secured to said ski axle andv disposed for rotation adjacent andparallel to said-shock pillar; a plurality of shock cord bands disposedto encircle the upper ends of said shock pillar and said ski pillar;means for positioning and retaining said bands on each of said pillars;a plurality of arcuateslots in one of said pillars concentric with thecenter of rotation of said ski pillar; and shear bolts secured to theother pillar and disposed for movement in said arcuate slots.

2. A ski positioning means for light airplanes, comprising: a tubularaxle adapted to be se- 4 cured, xedly, to an airplane landing gear; avertically disposed shock pillar flxedly secured to said axle; a skiaxle, co-axially disposed with and revolvably supported by, said tubularaxle; means for securing said ski axle xedly to a landing ski; a skipillar xedly secured to said ski axle and disposed for rotation adjacentand parallel to said shock pillar; a plurality of shock cord bandsdisposed to encircle the uper ends of said shock pillar and said skipillar; means for positioning and retaining said bands on each of saidpillars; a plurality of arcuate slots in one of said pillars concentricwith the center of rotation of said ski pillar; shear bolts secured tothe other pillar and disposed for movement in said arcuate slots, andsaid slots having different lengths to provide a step-by-step overloadshear bolt stop.

3. A ski positioning means for light airplanes, comprising: a tubularaxle adapted to be secured, ixedly, to an airplane landing gear; avertically disposed shock pillar l'lxedly secured to said axle; a skiaxle, co-axially disposed with and revolvably supported by, said tubularaxle; means for securing said ski axle xedly to a landing ski; a ski wpillarxedly secured to said ski axle and disposed ing 4said bands oneach of said pillars; a plurality of arcuate slots in one of saidpillars concentric with the center of rotation of said ski pillar; shearbolts secured to the other pillar and disposed for movement in saidarcuate slots, and said slots being disposed at different distances fromthe ski axle to provide a step-by-step overload shear bolt stop.

pillar xedly secured to said ski axle and disposed for rotation adjacentand parallel to said shock pillar; a plurality of shock cord bandsdisposed to encircle the upper ends of said shock pillar and said skipillar; means for positioning and retaining said bands on each of saidpillars, and additional means for connecting the shock pillar and theski pillar to limit the amount of their relative rotation.

HERBERT G. HAGER.

No references cited.

